Telecommunications services provided by each telecommunications service provider are usually limited to certain restricted geographical areas. Convenient contractual arrangements involving billing for past services rendered are in place only for those customers usually located in the area served by each service provider. All others must normally use prepay systems such as pay telephones to obtain service. That may be inconvenient for long distance callers, as a large amount of currency or a particular credit card or phone card must be available. Further, an international traveler who is not fluent in the language of the region served by a telecommunications service provider has an additional burden in using the telephone in that instructions in his native language on how to use the telephone are normally unavailable.
Pre-paid telephone services based on a pre-paid calling card have been implemented for access through the current Public Switched Telephone Network (PSTN). An example of a current system is illustrated in FIG. 1. A calling party 120 establishes a connection 116 with an originating switch 110 in the PSTN 114. The connection 116 includes an “in-band” connection. An “in-band” connection, as used herein, is a connection capable of carrying a voice frequency, a data stream or other information that is the “primary” conveyance of the network, along with in-band signaling information that is used to establish calls and/or services. Many telephone systems use some form of in-band signaling, wherein tones within the voice frequency band are used to carry signals such as dialed telephone numbers or other switching information. Such signaling occupies bandwidth that could otherwise be used for voice. Many modern telephone systems use, either exclusively or in combination with in-band signaling, out-of-band signaling, wherein information is transmitted via separate facilities or over separate frequency channels or time slots from those used to carry the voice or primary other information. One example of an out-of-band system used widely in telephone systems today is SS7 (ITU Signaling System 7), with associated protocols including ISUP (ISDN User Part) and TCAP (Transaction Capability Application Part). Further references herein to SS7 will be deemed to include those associated protocols. Other vehicles that could be used for out-of-band signaling include ISDN (Integrated Services Digital Network), Frame Relay, ATM (Asynchronous Transfer Mode) and IP (Internet Protocol). The terms “in-band” and “out-of-band” as used herein shall refer generally to signaling transmitted within or outside a primary information-carrying band.
Returning to FIG. 1, the calling party 120 designates the connection 116 as a prepaid call, usually by dialing a number dedicated to that purpose, such as a toll free number having a prefix in the form of “8YY”. The originating switch 110 then connects the call through an intermediate switch 130 to a switching system 142 within the prepaid card platform 140. That platform, including its switches and other components, is typically located at a centralized site that may not be near either the calling party 120 or the called party 124. The connection 128 between the originating switch 110 and the intermediate switch 130, and the connection 132 between the intermediate switch 130 and the platform switching system 142, are supported by out-of-band connections. The subsequent information collected by the platform 140 is all done in-band which forces the call to stay connected to that location for the entire length of the call.
The platform switching system 142 connects to a host computer 150 through a connection 144. The host 150 accesses a service management computer 154 to verify the prepaid account using data in a prepaid card database 156 and to decrement the time available in the account as it is used. The host 150 also accesses a call record database 148 for call processing and switching.
The platform switching system 142 sets up a connection 146 with a voice response unit (VRU) 152. The connection 146 includes in-band capacity. A VRU is a menu-driven user interface for exchanging information ‘in-band’ from a customer connected through a voice telephone. In the present case, the VRU 152 collects a prepaid card number and the called/dialed number from the customer and informs the customer whether the card is valid and how much time is left on the card.
Once it is verified that the prepaid card is valid and has sufficient time for completing a call, the platform switching system 142 establishes a connection 131 through intermediate switch 130 and connection 126 with a terminating switch 112, which connects through connection 118 to the called party 124. Each of the connections 131, 126, 118 have in-band capability.
The connections 126, 128, 131, 132 require two termination points each (one at each end) and consume four extra terminations in the AT&T Network and two extra terminations in the prepaid platform location, along with extra bandwidth.
One example of a system having a platform architecture similar to that described above is described in U.S. Pat. No. 5,353,335, issued Oct. 4, 1994 to D'Urso et al., which is assigned to the same assignee as the present application, and hereby incorporated by reference herein. That patent describes a prepaid telephone system having multilingual capabilities.
Existing prepaid card platforms such as that described with reference to FIG. 1 utilize significantly more bandwidth and switching terminations than a simple station-to-station connection. That is primarily because of the number of connections necessary to route the call through the switching system associated with the prepaid card platform. It is therefore desirable to provide a method and system for placing a prepaid card call that does not consume a large amount of bandwidth and a large number of terminations, while still providing access to a service management computer and the associated databases.